Supplementary Material for: Post-operative severity assessment in sheep

Introduction: Sheep are frequently used in translational surgical orthopedic studies. Naturally, a good pain management is mandatory for animal welfare, although it is also important with regard to data quality. However, methods for adequate severity assessment, especially considering pain, are rather rare regarding large animal models. Therefore, in the present study, accompanying a surgical pilot study telemetry and the Sheep Grimace Scale (SGS) were used in addition to clinical scoring for severity assessment after surgical interventions in sheep. Methods: Telemetric devices were implanted in a first surgery subcutaneously into four German blackheaded mutton ewes (4-5 years, 77-115kg). After three to four weeks of recovery, sheep underwent tendon ablation of the left M. infraspinatus. Clinical scoring and video recordings for SGS analysis were performed after both surgeries and heart rate (HR) and general activity were monitored by telemetry. Results: Immediately after surgery, clinical score and HR were slightly increased and activity was decreased in individual sheep after both surgeries. The SGS mildly elevated directly after transmitter implantation, but increased to higher levels after tendon ablation immediately after surgery and on the following day. Conclusion: In summary, SGS and telemetry-derived data were suitable to detect post-operative pain in sheep with the potential to improve individual pain recognition and postoperative management, which consequently contributes to refinement.